You must customize these settings. The default settings are too permissive for regulated industries (Finance, Healthcare, Legal) and too restrictive for engineering firms that rely on legacy CAD-to-Excel exports.
If you use Group Policy, always set the "Set Default File Block Behavior" policy. This determines whether the user sees an error message, a warning, or a silent failure. The worst thing you can do is block a file type without a clear error message—your helpdesk will drown in "corrupted file" tickets. The "Open Anyway" Loophole (And Why You Should Close It) By default, when a file is blocked by these settings, the user gets a message and no option to override . However, older versions of Office (2010/2013) had a checkbox: "Do not show this message again and allow me to open." file block settings in the trust center
In essence, these settings tell Word, Excel, PowerPoint, and Visio: “When you encounter a file saved in [X format], do not let the user open it—or, at the very least, do not let them save to it.” You must customize these settings